# GPU & hardware

> Throwing silicon at the wall: GPU ports, FPGA pipelines, distributed sweeps, and the perennial quantum proposal. This is the ledger of what each one actually delivered, and why the wall it meets is memory and structure, not arithmetic.

- Canonical page (with interactive figures/demos): https://eternity2.dev/research/build/hardware/
- Updated: 2026-07-13

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Throwing silicon at the wall: GPU ports, FPGA pipelines, distributed sweeps, and the perennial quantum proposal. This is the ledger of what each one actually delivered, and why the wall it meets is memory and structure, not arithmetic.

The pages below go technique by technique: what each is in a line, what it
actually reached on the real 16×16 board, where it stops, and the labs and
measurements to back it. For the whole territory at once, start with
[a map of every known approach](/research/build/approaches-map).

## Pages in this section

- [GPU solving: the wall is memory, not arithmetic](https://eternity2.dev/research/build/hardware/gpu-solving) — Eternity II looks like the perfect GPU workload: millions of independent subtrees, embarrassingly parallel. Eighteen years of community attempts measured a different reality: divergent branching, per-thread state that outgrows fast memory, and a placement loop that was already memory-bound on CPUs. What the GPUs actually delivered, and the one workload where they genuinely shine.
- [FPGA solving: mapped but never driven](https://eternity2.dev/research/build/hardware/fpga-solving) — If the placement loop is memory-latency-bound, an FPGA looks like the exact answer: put the lookup tables in on-chip block RAM one cycle away, and pipeline dozens of tiny backtrackers on one die. The community mapped this road in detail. Michael Field designed the solver, projected 5 billion placements per second per chip, and ran a prototype on real silicon. Then the road was never driven to the end. The complete record, and why.
- [Quantum approaches: two speedups at their true price](https://eternity2.dev/research/build/hardware/quantum) — The quantum computer is the list's oldest deus ex machina, invoked in the puzzle's first month and every few years since. There are exactly two real stories to tell: Grover's quadratic speedup, and annealing on a QUBO encoding. This page tells both properly, does the arithmetic against Eternity II's actual numbers, and reports the complete community record: nineteen years of asides, one unfinished embedding attempt, zero runs.

## Related

- [A map of every known approach](https://eternity2.dev/research/build/approaches-map) — The survey the community keeps asking for and never finds: every family of attack tried on Eternity II, what each one actually reached, where it walls out, and a link to the deep page. One organising insight runs through all of them.
- [The techniques](https://eternity2.dev/research/build/techniques) — The technique shelf: the algorithms and pruning ideas that recur in every serious Eternity II solver, each with what it is, what it costs, and what it actually bought when measured on this puzzle.